Field of the Invention
The present invention relates to a method for manufacturing a liquid-ejecting head for ejecting liquid such as ink as a drop.
Description of the Related Art
In a liquid-ejecting head that ejects liquid as drops for forming a photograph, a document, a 3-dimensional structure and the like, liquid paths for receiving the liquid from tubes or tanks and directing it to plural ejection elements are formed. For example, Japanese Patent Laid-Open No. 2002-178538 discloses a form of forming a groove shape in a liquid path in order to prevent the supply of liquid from being obstructed due to the occurrence of air bubbles. Moreover, for example, in the case of a color-inkjet printing head that receives plural inks and leads those inks to corresponding ejection elements, flow paths from ink-supply openings to the ejection elements must be prepared independently for each color of ink. In this case, it is also necessary to have hollow internal construction in which the size of liquid chambers for temporarily storing the respective inks can be maintained to a certain extent, and that bends in guiding each of the inks to ejection elements for each color that are highly densely arranged in a narrow area. Therefore, in recent liquid-ejecting heads, that hollow internal construction has become complicated.
Typically, from the aspect of ease of manufacturing, lightness and prevention of corrosion, the liquid paths in a liquid-ejecting head are often formed in a resin mold. Japanese Patent Laid-Open No. 2002-307709 discloses a method of simultaneously forming plural parts at different locations inside the same mold, and then joining the parts later inside the same mold in order to achieve the complicated internal construction as described above. Hereafter, this kind of manufacturing method will be called die slide injection molding. By employing die slide injection molding, it becomes possible to efficiently manufacture molded parts having complicated internal construction with high precision.
Incidentally, there is a process in die slide injection molding in which after two parts that will be joined together are formed simultaneously at different locations inside the same mold, the mold is opened so that the parts will remain on a specified side.
However, as described above, when parts have complicated internal construction as in recent years, there are cases in which it is difficult with conventional methods to keep each of the parts on a specified side when opening the mold. More specifically, in each of the parts, the separation resistance with respect to the side having the more complicated shape becomes larger than the separation resistance with respect to the other side, so it becomes easy for parts to remain on the side having the more complicated shape. When the side on which it is easy for a part to remain differs from the specified side, the progression of the molding process is obstructed, and there is a drop in the productivity of a process for manufacturing a liquid-ejecting head.